国外文献摘要

内螺纹管内的二相流传热系数的研究近几年来,由于电站锅炉的高温高压化和二相流偏离核态沸腾(英文缩写为DNB)研究的进展,炉膛水冷壁管采用内螺纹管的锅炉增加,并正在研究在极其严酷的吸热条     

内螺纹管内两相流体传热系数的研究

0 前言内螺纹管的开发是用来大幅度改善炉膛水冷壁管的两相流体偏离核态沸腾(DNB)的特性,但对大范围压力的DNB改善效果尚不清楚,且存在阻力损失大等问题,因此过去其应用场合较少。而近年来由于锅炉高     

600MW超临界循环流化床锅炉水冷壁的选型及水动力研究

在超临界及亚临界压力范围内对不同尺寸的内螺纹管和光管的流动传热特性进行了实验研究,得到了偏离核态沸腾(DNB)和蒸干(DRYOUT)的发生规律、管子流动和传热的特性,建立了计算复杂流动网络系统回路流量及节点压力的数学模型,对非线性方程组采用迭代方法进行了求解,并对1台600 MW超临界循环流化床锅炉的水冷壁流量分配及壁温分布进行了计算.结果表明:在BMCR和在75%BMCR负荷下锅炉运行是安全可靠的.另外,笔者还研究了吸热偏差对流量分配及壁温分布的影响,结果表明流量与吸热量呈正响应特性.     

高压锅炉中的内螺纹管的腐蚀与沉淀

前言在许多高压锅炉的设计中,要在所有的汽水回路里得到足够的质量流速是设计者难以做到的。增加下降管和上升管的流通截面可使质量流量增多,但这会使锅炉成本提高。为了在多种运行工况下不必靠较高的质量流速而能避免偏离核态沸腾(DNB),拔柏葛公司发展了一种内螺纹管,经过试验已在许多高压锅炉的炉膛内使用了这种内螺纹管。本文将讨论在已运行的高压锅炉上取样发现的内螺纹管的腐蚀和沉淀问题。     

火电厂锅炉给水温度耗差分析模型的建立

分析了锅炉给水温度变化对火电厂机组热经济性的影响,在考虑了给水温度对锅炉效率影响的前提下,建立了锅炉给水温度偏离目标值时的耗差分析模型,利用该模型对某电厂300MW机组运行参数进行耗差计算,其结果可以满足精度要求.     

240t/h锅炉刚性梁锁扣改造

240 t/h锅炉运行期间由于锅炉刚性梁的频繁晃动、刚性梁锁扣松动,导致锅炉水冷壁管被撕裂、水冷壁管发生泄漏事故,通过对锅炉刚性梁锁扣的改造,有效地避免了锅炉刚性梁的晃动,确保了锅炉的稳定运行.     

670t/h锅炉结焦原因分析与燃烧器改造

煤粉锅炉燃烧时,结渣是锅炉一直存在的问题.锅炉设计煤种和燃烧方式存在着不适应,就容易导致炉膛结渣.锅炉燃烧煤种偏离设计煤种,而对燃烧的煤种特性分析不够深入,锅炉在燃烧时,由于燃烧器本身的调整不能适应煤种多变的情况,最终将导致炉膛结焦,甚至出现因结渣而引发锅炉停运.针对670 t/h锅炉因煤种和燃烧方式不相适应而导致炉膛结焦的原因进行分析,并对锅炉燃烧器进行重新布置,改善炉膛结焦.     

锅炉"四管"泄漏原因浅析与防治

火力发电厂中,锅炉“四管”是重要的设备之一,锅炉“四管”的安全稳定运行,与发电机组的安全稳定经济运行是密不可分的.火电机组一旦发生锅炉“四管”泄漏就只有采取强迫停炉,进行抢修,严重影响火力发电厂的正常生产,造成巨大的经济损失.本文简要分析了锅炉“四管”泄漏的原因,提出了防止锅炉“四管”泄漏的综合技术措施.     

超(超)临界压力锅炉垂直管屏水冷壁水动力与热偏差调整建议

垂直管圈超(超)临界压力锅炉一般都在水冷壁管入口安装节流圈,以调节工质流量,使其与对应区域的热负荷相匹配,但是该类型锅炉在投运后往往出现水冷壁节流圈结垢、水动力和热偏差,以致发生爆管.通过对水冷壁结构特点的分析,对爆管原因进行了研究,参考亚临界垂直管圈直流锅炉水动力调整经验,提出超(超)临界压力锅炉垂直管屏水冷壁系统改进和进行水动力调整的建议,即减少水冷壁管入口节流圈数量,在水冷壁管(屏)的入口安装调节装置以及加装水冷壁管屏的监视测点等.     

670t/h锅炉飞灰可燃物偏高的原因及对策

漳泽发电厂原苏制670t/h锅炉飞灰含碳量由于受设备系统、燃烧工况、煤粉细度,燃料性质等诸多因素影响,严重偏离设计值,致使锅炉燃烧效率降低.通过调整试验,找出了降低飞灰可燃物的有效措施,提高了锅炉机组经济性.     

浅析磨合期汽车的使用

如何合理使用磨合期的汽车，使其摩擦机件的磨损量能够平稳、均匀地磨合而不至于过度磨损，对汽车实际使用寿命有着重要的意义。从机器磨合期的特点和磨损机理出发，对汽车磨合期如何正确使用进行了有实际意义的探讨。     

10月份煤炭市场供需形势综述

通过对我国10月份煤炭产量的分析,表明我国煤炭市场需求增势强劲,价格呈现了持续攀升的良好势头,同时指出受市场供需及其他因素的影响,近期煤炭价格还会上涨,煤炭供应和销售问题仍应引起有关方面重视。     

高压变频器在炼铁厂节能改造中的应用

叙述了高压变频器系统的功能与节能效益,指出高压变频器应用于除尘系统的技术改造可提高设备的自动控制水平,还能达到节能降耗的目的。     

计算流体力学在发动机冷却水套设计中的应用

针对某三缸发动机在试验中出现的“拉缸”现象,应用STAR-CD软件对该机冷却水套中的流场和温度场进行分析,发现水套中存在大范围的低流速区和高温区,通过调整气缸垫中机体通往缸盖分水孔的大小和分布设计了改进方案,利用STAR-CD软件分析得到了最终的优化方案。     

One—Dimensional Analysis of Thermal Choking in Case of Heat Addition in Ducts

IntroductionThe s up ersonic- combus t ion ram j et (s cramj et ) engine is one of the most prollilsing air breathing prOPulsion systems for hypersonic transports. It is essentialto the design of scramjet engines that the fueLair miX-ture remains supersonic throughout the combustor.The subsonic combustion is better than the supersonic combustion from a standpoint of efficiency, bescause total pressure losses in heated supersonic flowsare higher than those in heated subsonic flows withsame st…     

Seasonal constraints in management of alternative sources of energy in rural areas

A plan for the management of alternative sources of energy, namely, wind, solar and biomass, available in a typical village of arid area has been formulated and it is found that the energy potential available in the village from mid February to mid September is much more than the energy requirement of the village; and during the remaining period the energy available is about 78.5 per cent of the energy requirement. Appropriate technologies for the effective and efficient use of these energies are earmarked so as to convert the energy potential available into useful energy.     

FHDO技术在混合二甲苯脱烯烃中的工业应用

催化重整生成油中富含芳烃和少量烯烃,要想生产合格的芳烃产品,必须脱除其中的烯烃。目前,广泛采用的脱除烯烃的方法是白土吸附和加氢精制工艺。抚顺石油化工研究院开发的FHDO技术,在成功应用于重整生成油苯、BTX等馏分脱烯烃基础上,首次在安庆石化1.0Mt/a催化重整装置混合二甲苯精制单元实现工业化应用。FHDO技术在较低反应温度(120~170℃)、反应压力(1.0~1.8MPa)、反应空速2~4h-1和氢油比(200~500∶1)下,生产出符合GB/T3407—2010的混合二甲苯产品。运行结果表明,HDO-18催化剂具有良好的活性和选择性,适用于催化重整生成油混合二甲苯馏分选择性加氢脱烯烃,FHDO技术可以有效替代常规的白土吸附和加氢精制工艺,从而彻底解决了常规混合二甲苯脱烯烃工艺中白土使用寿命短、需要频繁更换和废弃白土污染环境问题,以及加氢精制工艺在深度加氢脱烯烃过程中,带来的芳烃损失偏高等问题。FHDO技术的成功应用,填补了国内在催化重整生成油混合二甲苯馏分选择性加氢领域的空白,也是今后芳烃脱烯烃工艺的发展趋势。     

Analysis of traditional rural houses in Turkey in terms of energy efficiency

Energy consumption of recent buildings in Turkey continues to increase, as it does around the world. Conversely, traditional rural house types perform well in terms of energy efficiency. This study investigated the energy efficiency methods applied in traditional rural houses in the rural Thrace region of Turkey, built using timber, stone and adobe construction methods. The energy-efficient characteristics of the sample structures were identified by investigating their site layout, plan types, building outer shell design and material specifications. This study concludes that in traditional rural houses, prevention of heat-loss has been regarded as highly important; solar energy is highly utilised and the colloquial architecture is well suited to the climatic conditions of the region. This study may contribute to the increased awareness of this subject among designers. The ecological characteristics of traditional rural houses can be applied to current buildings by evaluating and replicating these characteristics.     

分层燃烧技术在炉前自成型装置中的应用

介绍了分层燃烧技术在正转链条锅炉炉前自成型装置中应用的结构原理,分析其燃烧过程,更好地解决目前单一的炉前自成型技术中出现的问题,进一步探讨炉前自成型技术的发展。     

Cathodic electrodeposition of SnS in the presence of EDTA in aqueous media

Cathodic electrodeposition in the presence of EDTA in aqueous solution was found to offer some noteworthy improvements in our attempt to synthesise an SnS thin film. EDTA has shown its capacity for improving the longevity of the deposition bath as well as the adhesion of the deposited film on a titanium substrate. Photoelectrochemical analysis reveals outstanding photoactivity of the electrodeposited thin film, while an optical study shows an energy gap of approximately 1.1 eV. The effects of chelating agent were extracted from the results of cyclic voltammetry, photoelectrochemical test, scanning electron microscopy and X-ray diffraction spectroscopy. The latter which displays better defined signals reaffirms the appreciable improvement in the polycrystallinity of the thin film. Analysis of peak locations, coincidentally, confirms that SnS of Herzenbergite form has been obtained.